Manchester United's Sir Alex Ferguson said his team had to persevere but they got their reward in the end. Photograph: Peter Powell/EPA

Sir Alex Ferguson hailed the endurance of his Manchester United team after the late goals that earned them a 2-0 win at Blackburn Rovers and put them five points clear of Manchester City at the top of the table.

The victory confirms United as strong favourites for a record 20th league title on the back of a 10-point swing over the past month. They were indebted at times to David de Gea's goalkeeping before Antonio Valencia, the game's outstanding performer, scored with a stunning 81st-minute shot. The substitute Ashley Young added the second five minutes later, in keeping with Ferguson's claim that no other team scores so many late, decisive goals.

"It was a long night, we had to persevere and persevere and we got our reward in the end but I have to admit that I thought for a long time it wouldn't come because we didn't make many clear-cut chances," Ferguson said. "That goal [from Valencia] is so important and it perhaps typifies the history of this club that we kept going and got our reward in the end.

"Scoring so late, it's typical of us, our history. We never stop trying, there's no question about that. It could be a very important moment."

Ferguson deliberately avoided talking more about where it leaves the title race but the fist-pumping victory salute from United's manager felt telling and the bookmakers have them at 1-8 to win the 13th championship of his 26 years in charge.

Their next three games are against Queens Park Rangers, Wigan Athletic and Aston Villa, all currently in the bottom six, before Everton visit Old Trafford, where they have not won for 20 years. After that it is the Manchester derby at the Etihad Stadium on 30 April.

United are on a run of seven victories on the bounce and, if they keep that going until their meeting with City, they could even afford to lose against their neighbours and still win the league.

"It was a big performance from us because Blackburn possess a great threat," Ferguson said. "They can hit the ball long and catch you on the break and they have a real goal threat about them, so to come through what was a very difficult game is an achievement. When Ryan Giggs came on [as a second-half substitute] he made a difference and when Ashley Young came on he made a big difference and we got there in the end.

"The important thing now is to win Sunday's game [against QPR]. But listen, they are all big games now. It doesn't matter if it is next Sunday, the following Wednesday [at Wigan], the Sunday after that [against Villa], they are all big ones. The players are prepared for that. We will fight right to the end in all the games for the right to win."

Ferguson praised Valencia as "the difference between the sides" but there was acclaim, too, for De Gea, the young Spaniard whose mistakes had helped Blackburn win 3-2 at Old Trafford in December and who was dropped for the following game at Newcastle as a result.

De Gea returned to the team after Anders Lindegaard was injured and has excelled ever since. "David made three fantastic saves that kept us in the game," Ferguson said. "He has done his bit for the team. He has really grown in stature, the boy. He was outstanding."

The defeat sends Blackburn back into the bottom three because their goal difference is two worse than QPR's, who move up a place to 17th. "When you have done so well and think you are going to get something, you can get a little bit down," the Blackburn manager, Steve Kean, said. "If we can play like that, we can get enough points. It's about keeping those standards now we are in the relegation zone."